If you've spent some time in old Saigon - or Ho Chi Minh City as it's now known - you will find the building familiar: grey stone that's become streaked by downpours over the years; the style of the architecture rather ornate, sort of inter-war imperial-municipal; a dark interior with what could be white tablecloths just about visible, suggestive that this official-looking but rather tattered building is now given over to another, more social activity.
But this isn't Saigon; it's a former council bath-house off the Kingsland Road in East London. The Vietnamese restaurant, Huong Viet, is housed in a place that became a Vietnamese cultural centre once its ablutional activities ceased. It was converted in the early '80s to help out the so-called Boat People who fled Vietnam as the victorious communist government tightened its grip following the fall of Saigon.
Like many immigrants, one of the first activities they turned to in order to earn some money in their new home was the restaurant business. Cooking and waiting: most communities have those skills no matter how disorientated they are. It's a local success story: Vietnamese restaurants are dotted around the East End, dominating the bottom of the Kingsland Road where trendy Hoxton meets equally trendy Shoreditch.
But it's not a national success story. Vietnamese cuisine - unlike Thai and even Japanese, more recently - hasn't conquered many other high streets. Which is a shame as it has some distinctive qualities that deserve wider appreciation.
Vietnamese food works particularly well during this very warm weather. It's almost unique (sushi providing another exception) in tasting as good when it's hot and muggy as when it's cooler. It's to do with the profusion of raw ingredients - fresh and crunchy vegetables and herbs mostly - which are combined with the hot food at the last minute (and often at the table). The clear broths sharpened with lime, coriander, basil and chili, as well as the odd, more exotic addition also turn out to be spectacularly refreshing (the national dish pho, a clear beef broth, is the classic).
But year-round, there's nothing quite like Vietnamese cuisine's combination of flavours and textures: soft, fat prawns; sweetly aromatic basil; intensely-flavoured barbecued beef; fragrant and enlivening mint; fierce little chilies, and more, much more (I'm making my mouth water just writing this - I have a serious Vietnamese habit).
Having been to Ho Chi Minh City a couple of times I can vouch that the food here is as authentic as the Huong Viet setting can be when you catch it on the right, really hot day, one that's ideally been humidified by a tropical-style downpour. We're lucky enough to have had a few of these recently and I've been lucky enough to accompany a few of them with a satisfying pho and a couple of summer rolls.
Despite these virtues and more - it's cheap too, and healthy, of course - Vietnamese cooking is not well-known in this country. There's no Vietnamese celebrity chef (where's the TV producer with the initiative to pluck a Vietnamese Jamie from one of the Kingsland Road kitchens?). And what's stranger is the lack of awareness of this East End cuisine-cluster even in London. We are lucky enough to have what is practically a Little Saigon in our midst. Other immigrant areas are better known: China Town in Soho, of course; what's now been branded Banglatown around Brick Lane; and even New Malden, which, we're reminded by the World Cup, is home to the largest number of Koreans outside Korea. However, the Vietnamese community's profile remains astonishingly low.
The Vietnamese team qualifying for the next World Cup might help. Or more prominent celebrations for Vietnamese New Year? Or perhaps, given the Banglatown rebrand, what they're lacking is a catchy name? If so, I suggest Vietville, with its nod to the French influences still discernible in Vietnamese culture.
As China Town is to Soho, so Vietville could be to Shoreditch, which with its creative types and its painfully fashionable bars, clubs and restaurants is sometimes described as the new Soho. And now the East London Line extension has started to provide a new and designer-cool link from here to the rest of the capital, there's really no excuse: take the next train to Vietville and be prepared to take on some serious refreshments.